import java.util.Scanner;
public class demo6 {
        public static void main(String[] args) {
            Scanner scanner = new Scanner(System.in);
            System.out.println("请输入圆的半径：");
            double r = scanner.nextDouble();
            zc(r);
            mj(r);
        }

        public static void mj(double r) {

            double s = r * r * 3.14;
            System.out.println("圆的面积：" + s);
        }

        public static void zc(double r) {
            double c = 2 * r * 3.14;
            System.out.println("圆的周长：" + c);
        }
    }

